The invention relates to an arrangement for reading a record carrier on which picture information has been recorded, which picture information represents a picture composed of pixels, which arrangement comprises
a picture memory having addressable storage locations for the storage of signal values representing the pixels of a still picture, PA1 video signal generating means for continuously generating a video signal at a predetermined picture rate, which video signal is defined by the signal values stored, which video signal generating means comprise PA1 means for carrying out a fetching process in which the signal values are periodically fetched from the storage locations of the picture memory in a predetermined sequence and means for converting the fetched signal values into the video signal, PA1 read means for reading picture information of a new picture recorded on the record carrier, and PA1 means for carrying out a loading process in which previously stored signal values in the storage locations are replaced by new signal values defined by the read-out picture information.
An arrangement of the type defined in the opening paragraph is known inter alia from U.S. Pat. No. 4,740,832. The arrangement described therein is a Compact Disc player for reading compressed picture information. After read-out this compressed picture information is decompressed. After this operation the picture is stored in the picture memory as a luminance bit map and two color bit maps. The luminance bit map contains the luminance information for each pixel of the video picture and the color bit maps represent the color information of the video picture with a horizontal and a vertical resolution lower than the resolution of the luminance information. The picture memory is of a type divided into two memory sections which can be addressed independently of each other and which are both accessible at the same time. One of the two memory sections stores the signal values for the even picture lines of the picture and the other memory section stores the signal values of the odd lines of the picture. The signal values in both sections each represent one field of the video picture. During display all the signal values of a field are fetched from the memory before the signal values of the next field are fetched, so that the two memory sections are used alternately for fetching the signal values. During the time in which the signal values are fetched from one memory section it is possible to adapt the signal values in the other memory section. As already stated, the vertical and the horizontal resolution of the stored color information is lower than the resolution of the luminance information. As during the generation of the video signal both the color information and the luminance information must be available for each pixel in the video picture the resolution is enhanced in an information adaptation process. This information adaptation process is performed by means of an additional circuit, to which the color information fetched from the picture memory is applied and which enhances the horizontal and the vertical resolution of the color information by means of interpolation techniques. For the vertical interpolation it is required that at the same time the color information of a plurality of color picture lines is available. This requirement is met by providing the additional circuit with a number of line memories for the storage of the color picture lines.
The known arrangement has several drawbacks. First of all, the fact that the picture memory comprises two independently accessible memory sections requires a large number of provisions. For example, two address buses are required to address the two memory sections, which is problematic merely because of the space required for this purpose. Secondly, the use of color line buffers for the storage of the color lines is undesirable because of the cost involved.